==================================================================
BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x771/0xac0
Read of size 4 at addr ffff88816c475c94 by task jfsCommit/124

CPU: 1 UID: 0 PID: 124 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_address_description+0x55/0x1e0
 print_report+0x58/0x70
 kasan_report+0x117/0x150
 jfs_lazycommit+0x771/0xac0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 5754:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x32d/0x660
 jfs_fill_super+0xc2/0xda0
 get_tree_bdev_flags+0x430/0x4f0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x319/0xdc0
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5603:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x40/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c5/0x640
 generic_shutdown_super+0x13d/0x2d0
 kill_block_super+0x44/0x90
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x3d3/0x460
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0x1fa/0x730
 do_syscall_64+0x353/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88816c475c00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 148 bytes inside of
 freed 256-byte region [ffff88816c475c00, ffff88816c475d00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16c474
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff888100041b40 dead000000000122 0000000000000000
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff888100041b40 dead000000000122 0000000000000000
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 057ff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5747, tgid 5746 (syz.0.15), ts 69269773297, free_ts 69253511494
 post_alloc_hook+0x1f9/0x250
 get_page_from_freelist+0x21fa/0x2270
 __alloc_frozen_pages_noprof+0x18d/0x380
 allocate_slab+0x79/0x5e0
 refill_objects+0x2d5/0x350
 __pcs_replace_empty_main+0x2bf/0x6b0
 __kmalloc_cache_noprof+0x3a7/0x660
 ____ip_mc_inc_group+0x518/0xdb0
 ip_mc_up+0x115/0x2e0
 inetdev_event+0xfca/0x15e0
 notifier_call_chain+0x1a5/0x3d0
 __dev_notify_flags+0x1aa/0x310
 netif_change_flags+0xde/0x1b0
 dev_change_flags+0x128/0x260
 dev_ioctl+0x7b4/0x1150
 sock_do_ioctl+0x23e/0x320
page last free pid 5587 tgid 5587 stack trace:
 __free_frozen_pages+0xc1e/0xd10
 rcu_core+0x78b/0x10a0
 handle_softirqs+0x225/0x840
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20

Memory state around the buggy address:
 ffff88816c475b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88816c475c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88816c475c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88816c475d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88816c475d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
